Ministers from countries all across Europe gathered in Istanbul today to sign a new Council of Europe convention on domestic violence at the Istanbul summit of the committee of ministers. Incredibly, the UK wasn't one of the signatories. The British government so far has not commented on its reasoning, but for a country that prides itself on being a leader on women's rights, its failure to sign so far is both a mystery and a serious disappointment.

The UK government has been sending out mixed messages when it comes to domestic violence, as Jon Robins has pointed out before. On the one hand, the home secretary, Theresa May, and the director of public prosecutions stress how serious this violence is and how determined they are to end it. On the other, the government is nibbling away determinedly at those services that are needed to fight violence, such as legal aid and protection for female asylum seekers who suffered domestic violence in their home country. And now it is reluctant to sign a groundbreaking new treaty that will truly make a difference throughout the European region.

Born in southeastern Turkey, Selvi was 22 years old and pregnant with her fifth child when I met her while conducting research for a report on domestic violence. Her husband started his attacks when she was pregnant with their first child. "That first time, he hit me, he kicked the baby in my belly, and he threw me off the roof," she said. In 2008, Selvi (her name has been changed for her protection) finally went to the police after her husband had repeatedly raped her and broken her skull and arm. But the police, after questioning her husband at the station, told Selvi: "There's no problem, we spoke to him, you're back together." This happened three more times. "I just cannot go to the police any more," she said.

Selvi's story encapsulates everything that can go horribly wrong when domestic violence is not taken seriously.

The landmark new Council of Europe convention on preventing and combating violence against women and domestic violence offers a comprehensive international legal instrument to address this type of abuse, and includes a monitoring mechanism to ensure its provisions are implemented.

Implementation is crucial, for Selvi's case is sadly not isolated. Less than five miles from the site where the convention was being signed, Zelal (not her real name) lives with her three children across the street from her ex-husband's home. One day, he grabbed her as she walked out of her house. She explained: "He held me, I screamed, 'Let me go'. He started beating me. There were a lot of people around us, but nobody did anything. He pulled my hair and covered my mouth, and he dragged me to my house. There he kicked me and I fell to the ground … He broke every possession I have in the house, every chair, every picture, everything. Then he took off my clothes and he raped me."

Zelal managed to escape, almost naked, and went to two different police stations, where she endured a barrage of questions, from, "Aren't you ashamed to tell me you were raped by your ex-husband?" to "Why are you bothering us with this?". She eventually managed to speak with a prosecutor, but he told her to come back after the weekend.

Zelal's ordeal is one of many documented in a new Human Rights Watch report on family violence in Turkey. The report documents the awful experiences of women of all ages in Istanbul, Ankara, Izmir, Van, Trabzon, and Diyarbakır as they endured violence and sought help from the state. Women and girls as young as 14 told of being raped, stabbed, kicked in the stomach when pregnant, beaten with hammers, sticks, branches, and hoses to the point of broken bones and fractured skulls, locked up with dogs or other animals, starved, shot with a stun gun, injected with poison, pushed off a rooftop, and subjected to severe psychological violence.

In Turkey, 42% of all women have experienced such physical or sexual violence committed by a husband or partner, according to a major university study. Turkey has implemented important legislative changes to its penal and civil codes to deal with this crisis, including the establishment of a legal framework for the protection of domestic violence survivors, giving them the option of requesting a protection order.

However, there are serious shortcomings in the implementation of these reforms. The Turkish government had helped a few women we interviewed, but many others said that police, prosecutors, and judges sent them back to their abusers or acted so slowly on emergency protection orders that their very purpose was defeated. Too few domestic violence shelters offer protection, and some even keep their doors shut for victims lacking proper documentation, or women with disabilities.

The Turkish government, which largely has good laws on the books, must systematically and actively improve their implementation and guarantee access to protection and justice for women like Selvi or Zelal who desperately need it.

How to end this pandemic of violence against women and girls that still affects a quarter of all women in Europe?

The European signatories to the new convention gathered in Istanbul can learn from Turkey's experience. Strong legislation is necessary to fight domestic violence, but it is not enough. Every woman who survives violence should have access to protection, whatever her ethnic background, legal status, sexual orientation, marital status, economic situation or profession.

The UK should start by signing the Council of Europe convention, not just for women in the UK, but to send a clear message to all other countries in the region: take the struggle against violence seriously.